In a Prospective study, 1200 patient were randomly selected to study the effect of a New drug. The drug will be given for 5 years and its association with cataract will be studied. What type of study is this?
**Core Concept**
This question is testing the understanding of the research study design, specifically the type of study that involves observing outcomes over a long period. In this scenario, a new drug is being administered to patients over 5 years to assess its association with cataract development.
**Why the Correct Answer is Right**
This study is an example of a **cohort study**. In a cohort study, a group of individuals who share similar characteristics (in this case, receiving the new drug) are followed over time to examine the development of a specific outcome (cataract). This study design allows researchers to establish a temporal relationship between the exposure (new drug) and the outcome (cataract).
**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because a **case-control study** is a study design where researchers select individuals with a specific outcome (cases) and compare them to individuals without the outcome (controls) to identify potential risk factors.
**Option B:** This is incorrect because a **cross-sectional study** is a study design where researchers examine a population at a single point in time to identify the prevalence of a specific outcome or risk factor.
**Option C:** This is incorrect because a **randomized controlled trial (RCT)** is a study design where participants are randomly assigned to either an intervention group (in this case, the new drug) or a control group to evaluate the effectiveness of the intervention.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that cohort studies can be further classified into prospective and retrospective studies. In this scenario, the study is prospective because it involves observing outcomes over time from the beginning.
**Correct Answer:** C.